Will I need to change my pump? This is a question we get asked a lot and this is the first in a series of FAQs answering common questions about tank cleaning and changing tank cleaning systems. The short answer to whether you will need a new pump for your CIP system is: possibly.

There are two limiting factors for a pump: the maximum pressure it can deliver and the maximum flow rate it can deliver. This is what needs to be considered when looking at changing tank cleaning systems.

Generally speaking, if the newly proposed tank cleaning system is lower in both required pressure and flow rate, then the existing pump will be fine and it won't need to be changed. If the required or ideal new pressure for the new tank cleaning system is higher, or the flow rate is higher, then there will be a possibility that the pump needs changing. However, this is not always the case.

Normally, when moving from a spray ball to a spinner (upgrading from a static spray ball to a spinning spray ball), the optimal pressures will be roughly the same. Whether or not the pump can operate at high pressure doesn’t need to be considered because it won’t need to; both these systems run at roughly the same pressure. When moving from spray balls to spinners, the overall flow rate for the spinner is, in almost all cases – and this is one of the reasons why we make that move – lower than in the spray ball.

Overall, moving from spray balls to spinners means that the existing pump is going to be fine.

Spray Balls                                          Spinners

If, for whatever reason, it is the other way round and you're downgrading in effect from a spinning spray ball to a static spray ball, then the flow rate of the new spray ball system needs to be looked at because if that's higher than the existing pump can deliver, you may need to change the pump to a higher capacity pump.

When moving from spinners and spray balls to rotary jet cleaners, it becomes more complex. Typically, these rotary jet cleaners work most efficiently at pressures above approximately six bar. Ideally, it needs to be kept within the eight to ten bar fluid pressure range. This is quite a lot higher than the two to three bar that is optimal for spinners and spray balls. Therefore, it is vital to ensure that the pump can actually deliver the required pressure. Flow rates, again, typically will go down when moving from spray balls to rotary jet cleaners.

Rotary Jet Cleaner 

The flow rate capacity of the pump is not the main concern here. Normally this would be fine, but that higher maximum pressure the pump can deliver is a worry; if it cannot deliver the required pressure, the pump will need upgrading.

However, things become more difficult when looking at certain pumps such as centrifugal pumps. This is because centrifugal pumps will deliver variable pressure depending on what the pipe system actually sees. Moving from a spinner running at three bar to a rotary jet cleaner that wants to run at six bar, if the flow rate for the rotary jet cleaner is considerably lower, that centrifugal pump may equalise at a higher pressure and a lower flow rate. A typical example would be moving from a spray ball running at three bar using 250 litres a minute, and imagine the rotary jet cleaner that you're proposing wants to run at six bar at 125 litres a minute; that same pump may well be able to do that.

At this stage, the pump curve needs to be checked to see whether it can cope with the lower flow rate, higher pressure scenario. That almost always requires a change of pump, especially a specialist high-pressure pump. The pipework is also likely to be in need of an upgrade, in all likelihood to high-pressure pipework.

If it can't, then the pump will need upgrading. But it's important to remember gravitational and frictional pressure loss as well. The pressure right at the pump is going to be different to the one delivered actually at the cleaning head. If you're moving to a high-pressure jet cleaning system, you're almost certainly going to need a new pump. High-pressure tank cleaning systems need between 50 and two hundred bar.

To recap:

You're not going to need to change your pump if the required pressure and flow rate on the new tank cleaning system are both lower in the new system than the old system.

You probably won't need to change your pump by moving from spray balls to spinners.

You may well need to upgrade your pump to be able to deliver the higher maximum pressure when upgrading from spinners or spray balls to jet cleaners, but you might get away with it if the flow rate is reduced and the pump naturally can settle into that high-pressure regime.

You will definitely need to change your pump when moving to a high-pressure system, and probably your pipework as well.